Refrigeration



' R. c. ROE 2,201,099

REFRIGERATION May 14, :1940.

Filed June 8. 1933 2 Sheets-Sheet 1 Ffyure 2.

May 14, 1940. Q ROE 2,201,099

REFRIGERAT ION Filed June a, 1933 '2 Sheets-Sheet 2 Wffdwvmmg- IATTORNEY Patented May. 14, 1940 UNITED STATES PATIENT OFFICE 3 Claims.(Cl. 82-115) My invention relates to improvements in refrigeration,particularly in water refrigeration under vacuum, and more particularlywater refrigeration under vacuum for air conditioning. A further objectof my invention is to provide air conditioning apparatus for the abovepurposes which does not contain obnoxious refrigeration fluids and whichwill operate without difliculty and trouble at high efliciencies. Otherobjects of my invention become apparent as the specifications appear andproceed.

In the present vacuum refrigeration practice, it is necessary to providea source of high pressure steam for the actuation of steam actuatedvacuum pumps and to have other cumbersome equipment which is not readilyavailable for this purpose. In my invention, as hereinafter set forth, Ihave simplified this art. I have provided a piece of equipment which ishermetically sealed and which can be used in small or moderate sizes inthe form of a self contained unit and that does not require a steamboiler or other steam producing apparatus of a similar character withits attendant complications and which will produce refrigeration with alower expenditure of power, a high efficiency and in a manner believedto be heretofore unknown in the art without the use of obnoxiousrefrigerants, all as hereinafter set forth.

In this invention, it is proposed to use blade screws of a type somewhatsimilar to the last wheels of a reaction turbine but differing therefromin the respect that they are compressing water vapor and not expandingwater vapor. Many years ago the eminent turbine designer, Parsons,developed the theory of compressing gases with reaction blading drivenby power. An

experimental machine was built at that time.

which was a failure. Later, work has been done on this in a mathematicalway by Dr. George De Bothezat and others which has demonstrated theprinciples involved in elastic fluid compression in this type of bladescrew. American practice on turbines using steam by expansion to producepower has been to have alternate rows of stationary and moving blades.Ljungstriim in Europe has developed a turbine in which the alternaterows of blades move in opposite directions, this turbine being used toproduce power, improving the efficiency of expansion of the steam bythis arrangement. In a similar manner, improvements in efficiency in thecompression of steam can be accomplished, provided the blade types andstructures are such as to function efliciently for compression purposesas distinguished from expansion purposes. The theory of this performancehaving been worked out'by others,

it is not the intention of thisapplication to claim the method orapparatus for compressing elastic fluids by blade screws, per se, butrather it is the c intention of this application to claim thecombination of this apparatus with other apparatus for the purpose ofproducing a new type of elastic fluid refrigeration heretofore unknownand believed to be an improvement in the art.

In the drawings, Figure 1 is a diagrammatic representation of a verticalcross section of a refrigerating apparatus, Figure 2 is a plan view of aportion of Figure 1, along lines 82-82, with a part cut away to showheat exchange tubes, 15 Figure 3 is a partial cross section of amultistage screw compressor driven by external power, Figure 4 is adiagrammatic representation of a general blade arrangement for thisapparatus.

In the figures, I is an evaporator, 2 is a fan, 3 is a condenser, 4 is,a blade screw compressor, 5 is a, drip pan, 5 is a heat exchangesurface in evaporator l, 1 is a water level in evaporator l, 8 is.avapor space in evaporator I, 8 is a float valve controlling liquidsupplied to evaporator I, I8 is a float controlling valve 9, H is alouver, i2 is a conduit, i3 is a conduit, i4 is a heat exchanger, IE isa vapor and air space in condenser 3, it are sprays, part of condenser3, H is a conduit, I3 is a blower, i9 is a water circulating pump, 28 isa motor, M is a water level interior to condenser 3, 22 is a water levelexterior to condenser 3, 23 is a city water supply line, 24 is a valve,25 is a float actuating valve 24, 26 is a conduit between valve 24 andheat exchanger l4, 2'! are heat exchange tubes interior to con- 35denser 3, 28 are fins to heat exchange tubes 21,

29 is an air duct from blower I8 to the lower portion of condenser 3, 30is an air space in the bottom portion of condenser 3, 3| are openingsfrom duct 29 to space 38 of condenser 3, 32 is a discharge connection toa flue, 33 is a motor driving blade screw compressor 4, 34 is a couplingbetween motor 33 and blade screw compressor 4. In blade screw compressor4, 35 is an external case or shell supported by stream line spiders 36and spider 31 and interconnecting evaporator I and condenser 3, 38 is ashaft connected to coupling 34; 39, 48, 4| and 42 are bearings, 43 is aspider connected to shaft 38 and rigidly keyed 5 thereon; 44, 45, 46,and 41 are blade rows connected to spider 43 and directly driven fromshaft 38, 48 is a rotating gear fastened to shaft 38, 49 is a stationarygear fastened to housing 5| and connected to stationary spider 36, 58 isa drain connection, BI is a housing as previously mentioned, 82 is acover over bearing 48 and enclosing the end nut 53 on shaft 38, 84 and55 are gears in mesh with gears 48 and 48 supported on shafts 53 and 51and rotating thereon,- 58 is a housing supporting shafts and El andenclosing gears 54 and 55 and gears 48 and 48 and running on bearings Hand 42, this housing rotating as will hereinafterbe explained in anopposite direction to shaft 38, 53 are blades from housing 58 to drum60, these blades being fastened rigidly both to housing 58 and to drum60, therefore rotating in an opposite direction to spider 43 as willhereinafter be explained, GI, 82, 63 and 64 are blades rigidly fastenedto drum 68 and rotating with said drum, 65 is a spider connected byblade 64 to drum 30 and supporting said drum by means of bearing 38 anddrum shaft 38, 86 and 61 illustrate general blade shapes and positionsand may be in pairs of succeeding blades in blade screw compressor 4, 68is an atmospheric water space in condenser 3, 69 is an internal waterspace in condenser 3, I is a conduit, II and I2 are lead and exitblocks, I3, i4, I5, I6, ll, 18,19,811 and 8| are close clearance endtightening shrouds, 82-82 represents extremities of section line showingsection as illustrated in Figure 2.

In operation, evaporator I, condenser 3 and interconnecting piece 35with their interconnections hereinbefore enumerated are made absolutelytight against leakage and are vacuumized and preferably hermeticallysealed. These parts have enclosed in them blade screw compressor t withits driving motor, said motor being connected through vacuum tightconnections electrically with connections on the exterior of the device(not illustrated). These devices also contain suitable refrigeratingfluid, preferably water, in a pure state, and therefore the pressurewhen standing is proportional to the temperature corresponding to thedevice, the whole device being highly vacuumized in general and voidedof all vapors except vapor of the refrigerant (water).

When operation is started, air is circulated over heat exchange surface21 in condenser 3 by means of blower I8, driven by motor 20 and at thesame time water is taken from external water space 68 in condenser 3bymeans of pump I9 via conduit II, through sprays I 6 and thence over heatexchange surface 21 and fins 28, back to water space 88, the air passingupward through heat exchange tubes 21 and around fin surface 28. Anyexcess heat in the apparatus is carried out in the air either by directcontact with the air passing through tubes 21 or by vaporization of thewater which vapor is carried out with the air. To replenish watervaporized in this manner, fresh water is supplied by conduit 23, floatvalve 24 under control of float 25, via conduit 26, heat exchanger I4,conduit I8.

Upon the starting of motor 33 by means of blade screw compressor 4 adifferential pressure is established between evaporator I and condenser3 and the temperature of evaporator I is lowered by evaporation of watertherein and the water therein cooled, this vapor being condensed incondenser 3 as will be hereinafter explained. Upon starting fan 2, airfrom the room is circulated over cool heat exchange surface 6 ofevaporator I which has been cooled by the evaporation of water caused bydifferential pressure as heretofore explained and heat from this air isabsorbed through said heat exchange surface 6 of evaporator Ito thewater interior to said evaporator. This water being evaporated by theaddi:

- 68 as evidenced by water level 2i and thence,

when and as needed in evaporator I to replace water evaporated in themanner heretofore described, it passes through conduit I3 to heatexchanger It where it is cooled by the interchange of heat to theincoming water through conduit 26 as heretofore explained and thencethrough conduit I2, valve 9 under control of float it, replenishingwater which has been evaporated from evaporator I.

It is thus seen that air in a room or from any other point which may behandled by fan 2 is lowered in temperature by transferring heat to wateron the interior of evaporator I, such water being vaporized. The vaporis compressed to a higher pressure by blade screw compressor 3, iscondensed in condenser 3 exchanging the heat which originated from theair being cooled together with the heat from mechanical losses with thecooling air or water circulating over the exterior of said condenser.The condensed vapor in the form of water is then returned by way ofscrew compressor 1 will have a compression duty of only 2 H.g. totalpressure.

The volume of water vapor leaving evaporator I will be approximately1702 cu. ft. per pound which is a very large volume on account of thelow pressure. Blade screw compressors as d are a very desirable type tohandle large volumes at low pressures with high efflciencies. With thepresent types of centrifugal compressors, it is possible to handle thesevolumes and small pressures at efficiencies not to exceed, with presentday practice and knowledge, about 65%, whereas with a properly designed,multi stage blade screw compressor adapted for the particular workinvolved in this application, it is expected that efficiencies in excessof 80% may be readily obtained. With the differences in emciences whichcan be obtained, it is very obvious that a combination of a blade screwcompressor with a sealed water refrigerating system is a desirable andefficient method of producing the differential pressure between theevaporator and the condenser. In order that the efiiciency of bladescrew compressor 4 may be maintained at its maximum, lead and exitblocks II and I2 are installed and close clearance end tighteningshrouds I3, I4, I5, I6, 11, I8, I9, 80 and 8I are provided, reducing theleakage of the steam around the ends of blade screws in a similar manneras is done in turbine practice in this country.

To explain the operation of blade screw compressor 4 in which the bladesdriven by shaft 38 revolve in one direction whereas the blades driven bydrum 68 rotate in the opposite direction, it should be borne in mindthat gear 48 is fastened fastened to housing 5|, and is stationary.Gears 54 and 55 are in mesh with gears 48 and 49. Gears 54 and 55,however, are in reality a two part gear, one part having a larger numberof teeth and pitch diameter than the other. A suitable arrangement todrive the drum and its attendant blades at the same speed in a reversedirection to the shaft would be to have gear 48 of 30 teeth and thatportion of gears 53 and 54 in mesh with gear 48 of 30 teeth and gear 49of teeth and that portion of gears 54 and 55 in mesh with gear 49 of 20teeth. Other arrangements may be provided which will accomplish the sameresult or if desired, arrangements may be made which will providedifferent speeds. In operation, gear 48 rotates by means of rotation ofshaft 38, rotating gears 54 and 55 in mesh therewith and gears 54 and 55rotate themselves around gear 49. Gears 54 and 55 being supported byhousing 58 which is connected with drum 60 by blades 59 cause thehousing and the drum and all interconnecting parts to rotate in theopposite direction than those parts firmly driven directly by shaft 38.This method of obtaining opposite rotation of blade screws in bladescrew compressors is believed to be new and novel.

Having described one embodiment of my invention according to patentstatutes, it is understood that my invention is capable of embodiment ina variety of 'forms of apparatus and that I am not limited to thespecific form of arrangement or structural parts shown and described butthat the scope of my invention is to be gauged by the accompanyingclaims taken in connection with prior art.

I claim:

1. A refrigeration system including: an evaporator and condenser havingconnections with one another, the whole arranged to constitute a cyclicpassage and maintained under relatively high vacuum; and a reaction-typepower-drivable axial-blade-screw compressor in said cyclic pas sage andin compressive relation from said evaporator to said condenser, theportion of said cyclic passage containing said compressor beingsubstantially straight from said evaporator to said condenser and theaxis of said compressor extending in the same general direction as theaxis of said portion of said cyclic passage.

2. A refrigeration system including: an evaporator and condenser havingconnections with one another, the whole arranged to constitute a cyclicpassage and maintained under relatively high vacuum; and areaction-typevmulti-stage power-drivable axial-blade-screw compressor insaid cyclic passage and in compressive relation from said evaporator tosaid condenser, the portion of said cyclic passage containing saidcompressor being substantially straight from said evaporator to saidcondenser and the axis of said compressor extending in the same generaldirection as the axis of said portion of said cyclic passage.

3. A refrigeration system including: an evaporator and condenser havingconnections with one another, the whole arranged to constitute a cyclicpassage and maintained under relatively high vacuum; and a reaction-typemulti-andreversed-rotation-stage power-drivable axialblade-screwcompressor in said cyclic passage and in compressive relation from saidevaporator to said condenser, the portion of said cyclic passagecontaining said compressor being substantially straight from saidevaporator to said condenser and the axis of said compressor extendingin the same general direction as the axis of said portion of said cyclicpassage.

RALPH C. ROE.

